HONOLULU — Low levels of perfluoroalkyl and polyfluoroalkyl substances (PFAS) were detected in water samples collected at the Pearl City Wells I Pump #2 of the Honolulu-Windward-Pearl Harbor water system, as well as Public Water System HI0000331, owned by the Honolulu Board of Water Supply (BWS). Pearl City Wells I Pump #2 serves the Pearl City area of the island of O‘ahu.

The detections of Perfluorooctane Sulfonic Acid (PFOS), which is one of the regulated PFAS, are below the U.S. Environmental Protection Agency’s (EPA) Maximum Contaminant Level (MCL) and are unlikely to pose a public health risk.

The detections of PFOS ranged from 2.2 to 2.4 nanograms per liter (ng/L), which is below the EPA MCL for PFOS of 4.0 ng/L. MCLs are the highest levels of contaminants that are allowed in drinking water by the EPA.

The detection of PFAS at the Pearl City Wells I Pump #2 was confirmed by samples collected on Sept. 9, 2025, and Sept. 15, 2025. The BWS formally notified the Hawaiʻi Department of Health (DOH) of the initial detection of PFAS via email on Sept. 30, 2025.

According to the EPA, PFAS, which have been used since the 1940s, are fluorinated organic chemicals that have been used extensively in consumer products such as carpets, clothing, fabrics for furniture, paper packaging for food and other materials (e.g., cookware) designed to be waterproof, stain-resistant or nonstick. They are also a component of fire-fighting foam and have many industrial uses.

For more information on PFAS, please see https://www.epa.gov/pfas or https://health.hawaii.gov/pfas. Users may also contact BWS.

This news release is issued in accordance with Hawaii Revised Statutes §340E-24(b), which requires notification of previously detected contaminants in underground sources of drinking water or any public water supply.

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